Non-grid-connected wind turbine with double-stator double-salient brushless dc-generator

Abstract

Disclosed is a non-grid-connected wind turbine generator system with high power, low cost and high efficiency. The wind turbine generator system includes a wind rotor, a generator and a tower. The wind rotor is a fixed-pitch variable-rotation-speed wind rotor, the wind rotor shaft directly drives a rotor of the generator, and the generator is a power-controlled DC generator, a double-salient brushless DC generator, or a double-stator double-salient brushless DC generator. The rotation speed of the fixed-pitch wind rotor is directly controlled by a power-controlled generator and thereby the attack angle of wind rotor blade is controlled. When wind speed is greater than rated wind speed of the system, the wind rotor is controlled into a state of blade stall so as to limit power output of the wind rotor and effectively broaden the wind speed range of wind rotor.

What is claimed is: 
     
       1. A non-grid-connected wind turbine generator system comprising a wind rotor, a generator and a tower, wherein the wind rotor is a fixed-pitch variable-rotation-speed wind rotor, the wind rotor shaft directly drives a rotor of the generator, and the generator is a power-controlled DC generator, a double-salient brushless DC generator, or a double-stator double-salient brushless DC generator,
 wherein the double-stator double-salient brushless DC generator comprises an inner stator, an outer stator and a rotor disposed between the inner stator and the outer stator; each of the inner stator, the outer stator and the rotor has salient poles, wherein each salient pole of the outer stator toward an inside of the outer stator is corresponding to each salient pole of the inner stator toward an outside of the inner stator, the number of salient poles of each stator is 6n; the number of salient poles of the rotor toward the outside of the inner stator and the number of salient poles of the rotor toward the inside of the outer stator is 4n respectively, where “n” is a positive integer; the salient poles of the rotor toward the outside of the inner stator are staggered with the salient poles of the rotor toward the inside of the outer stator by a mechanical angle of 60°/4n; each salient pole of the outer stator is provided with an armature winding, wherein the armature windings on the salient poles having the same phase are connected in series to form one phase; each salient pole of the inner stator is provided with a concentrated armature winding, wherein the armature windings on the salient poles having the same phase are connected in series to form one phase; and the outer stator and the inner stator are embedded with exciting windings respectively. 
 
     
     
       2. The non-grid-connected wind turbine generator system as set forth in  claim 1 , wherein the rotation speed of the fixed-pitch variable-rotation-speed wind rotor is adjusted by controlling an exciting current of the generator so that the wind rotor is always in a state of high efficiency operation; and when wind speed is greater than rated wind speed of the system, the wind rotor is controlled into a state of blade stall so as to limit power output of the wind rotor.